Electrode connection for discharge tubes



Oct. 31, 1933. H} MULLER 1,932,635

ELECTRODE CONNECTION FOR DISCHARGE TUBES Filed April 6, 1927 INVENTOR QHANS MULLER BY /LZ ATTORNEY Patented Oct. 31, 1933 UNITED STATES PATENTOFFICE ELECTRODE CONNECTION FOR DISCHARGE TUBES Application April 6,1927, Serial No. 181,394, and in Germany April 24, 1926 Claims.

5 In one method of building dish-shaped or flared on the metal ring 9.

tubes the grid is secured or attached to the tube by the aid of ametallic ring, while a separate current supply lead to the grid isprovided, for instance, by means of a wire lead-in sealed lat- 0 orallyin the tube. In the case of tubes of comparatively large power this sortof grid lead-in is unsuited because of the large grid currents carriedby the lead-in. For this reason the current supply has been connected tothe metallic caps or metallic rings which are sealed in the tube as partof the tube wall.

The invenion relates to a particularly suitable construction ofwelded-in or sealed-in current leads. The leads may also serve as asupport or carrier for the grid structure or other electrodes.

One embodiment of the invention is illustrated in the drawing, althoughit is to be herein understood that I do not desire to limit myself tothe exact structure shown and my invention applies equally well to ananode or cathode mounting or a mounting of all the electrodes. Fig. 1shows a transmitter tube. Fig. 2 drawn to an enlarged scale shows theessential features of a tube in accordance with this invention. The wall1 of the tube is made of glass and the cylindrical part 3 is made frommetal and serves as a watercooled plate or anode. Although the drawingdiscloses the anode as part of the tube wall, it is obvious neverthelessthat the anode may be inserted within the exhausted tube and form nopart of the tube wall.

The glass wall 1 of the tube is flared inwardly at 14 and one end of themetallic ring 9 is sealed or welded thereto. A flared or dished glasscap 2 is sealed to the other end of ring 9 which makes a completelyenclosed tube with the ring 9 as part of the tube wall. As shown inenlarged Fig. 2 the ring 9 may be externally threaded and the gridsupporting element 11 may be screwed thereto.

The cathode filament 4 may be wound loop or helix fashion and issupported by two holder or anchor wires 5 and 6 passed thru the bottomof the flared cap 2. It is further supported in an elastic and insulatedmanner from the grid supporting wire 7 by means of the elastic element12 and the insulating body 13. The said supporting wire 7 which carriesthe grid is secured A metallic cylinder 10 may be united with the ring 9by an internal screw thread in the ring 9, said metal cylinder 10 beingunited with those parts of the arrangement whose potential is to beimparted to the grid.

The invention lies in the metallic ring 9 or a plurality of such ringsbeing a part of the tube wall. These rings may be made of copper orother metal and are welded into the flared cap 2. The ring serves as asupport for the grid structure in that the carrier or anchor wires 7-7are attached thereto, as well as to permit a large flow of current tothe grid. The advantage of this arrangement resides in providing asingle element in the tube for attaching the grid or any electrodestructure; in eliminating lead wires passing through the glass walls andalso in providing large conducting bodies for the passage of largecurrent to the grid 01' other electrode.

What is claimed is:

1. An electron discharge device comprising an enclosure having aninwardly projecting stem, a metal ring hermetically sealed at one end tosaid stem, a cup-shaped insulating member hermetically sealed to theother end of said ring member, a plurality of electrodes within theenclosure, leads extending from one of said electrodes to said ring, anda conductor connecting said ring with an external source of potential.

2. An electron discharge device comprising an enclosure having aninwardly projecting glass stem, an internally and externally threadedmetallic ring having one end hermitically sealed to said stem, acup-shaped insulating member hermetrically sealed to the other end ofsaid ring, a threaded metallic tube adapted to be screwed into saidring, a plurality of electrodes within the enclosure, leads extendingfrom one of said electrodes to said ring, and means on said leads forscrewing said leads to said ring.

3. In an electron discharge device, the combination with an evacuatedenvelope having a tubular reentrant portion which comprises a pair ofaxially spaced cylindrical glass portions and an intermediate annularconducting member sealed to said glass portions, of an electrode withinsaid envelope and wholly supported from said conducting member, and alead-in conductor for said electrode disposed outside the envelope andconnected to said conducting member.

4. In an electron discharge device, the combination with an evacuatedenvelope having a tubular reentrant portion which comprises a pair ofaxially spaced cylindrical glass portions and an intermediate annularconducting member cond ucting member.

sealed to said glass portions; said annular conducting member havinginternally and externally threaded surfaces, of an electrode within saidenvelope, an internally threaded member engaging with the externallythreaded surface of said conducting member for supporting saidelectrode, and a lead-in conductor for said electrode disposed outsidethe evacuated envelope and having one end-externally threaded forengaging with said internally threaded surface of said HANS MULLER.

